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.Dd October 23, 2017
.Dt AIO_SUSPEND 2
.Os
.Sh NAME
.Nm aio_suspend
.Nd suspend until asynchronous I/O operations or timeout complete (REALTIME)
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In aio.h
.Ft int
.Fn aio_suspend "const struct aiocb *const iocbs[]" "int niocb" "const struct timespec *timeout"
.Sh DESCRIPTION
The
.Fn aio_suspend
system call suspends the calling process until at least one of the
specified asynchronous I/O requests have completed, a signal is
delivered, or the
.Fa timeout
has passed.
.Pp
The
.Fa iocbs
argument
is an array of
.Fa niocb
pointers to asynchronous I/O requests.
Array members containing
null pointers will be silently ignored.
.Pp
If
.Fa timeout
is not a null pointer, it specifies a maximum interval to suspend.
If
.Fa timeout
is a null pointer, the suspend blocks indefinitely.
To effect a
poll, the
.Fa timeout
should point to a zero-value timespec structure.
.Sh RETURN VALUES
If one or more of the specified asynchronous I/O requests have
completed,
.Fn aio_suspend
returns 0.
Otherwise it returns -1 and sets
.Va errno
to indicate the error, as enumerated below.
.Sh ERRORS
The
.Fn aio_suspend
system call will fail if:
.Bl -tag -width Er
.It Bq Er EAGAIN
the
.Fa timeout
expired before any I/O requests completed.
.It Bq Er EINVAL
The
.Fa iocbs
argument
contains more asynchronous I/O requests than the
.Va vfs.aio.max_aio_queue_per_proc
.Xr sysctl 8
variable, or at least one of the requests is not valid.
.It Bq Er EINTR
the suspend was interrupted by a signal.
.El
.Sh SEE ALSO
.Xr aio_cancel 2 ,
.Xr aio_error 2 ,
.Xr aio_return 2 ,
.Xr aio_waitcomplete 2 ,
.Xr aio_write 2 ,
.Xr aio 4
.Sh STANDARDS
The
.Fn aio_suspend
system call
is expected to conform to the
.St -p1003.1
standard.
.Sh HISTORY
The
.Fn aio_suspend
system call first appeared in
.Fx 3.0 .
.Sh AUTHORS
This
manual page was written by
.An Wes Peters Aq Mt wes@softweyr.com .
